by Mike Garafolo, USA TODAY Sports

by Mike Garafolo, USA TODAY Sports

Matt Moore obviously believes the Miami Dolphins are building themselves into a contender.

The career backup quarterback and spot starter could've taken advantage of a weak free-agent market at his position and found a spot to give him a better shot at a No. 1 job. Instead, Moore has re-signed with the Dolphins as Ryan Tannehill's backup. Terms of the agreement were not immediately available.

Moore is the second potential free agent the Dolphins, who entered the offseason with more than $40 million worth of cap space to work with, have kept in house with a new deal. Wide receiver Brian Hartline put his signature on a five-year, $30.775 million contract Thursday night.

Defensive tackle Randy Starks received the franchise tag Monday.

The Dolphins are still looking to add weapons around Tannehill, with wide receiver Mike Wallace being a likely target. Keeping Hartline and Moore in the mix is certainly a good start before the three-day period to negotiate with other teams' free agents begins Saturday.

Moore, 28, joined the Dolphins in 2011 as a free agent after four seasons with the Carolina Panthers. He started 12 games that season and posted modest numbers: 2,497 yards, 16 touchdowns and nine interceptions for a team that went 6-10 in Tony Sparano's last season as coach. Moore played in only two games last year as Tannehill earned the starting job in preseason.

Moore, a scrappy player with a good arm and decent mobility, could've spoken to teams like the Arizona Cardinals and New York Jets to see if he had a shot at beating out their incumbent quarterbacks. But his decision to remain in Miami has depleted an already-thin market and will allow Kevin Kolb, Mark Sanchez and a few other quarterbacks to breathe a little easier.